The Uchiha and the Avenger
by Sasukechidori16
Summary: While searching for a good Jeanne D arc alter story i realized there is a severe lack of them. So i decided to write my own. In this story Sasuke is transported from the 4th great ninja war to Chaldea where he meets Olga. This story will take place during the Fate Grand Order storyline (but with my own twist). So all you Jalter fans enjoy and good luck on your pulls.
1. Chapter 1

The Uchiha and The Avenger Chapter one

So while playing Fgo this story came to me.

"Speaking out loud"

'Inner dialogue'

Chapter 1: The Awakening

Sasuke has finally rested his eyes after transplanting his brothers into his own granting him the eternal mangekyou sharingan. Currently he's on his way to the battlefield to take part in the 4th ninja war.

"I'm pretty sure Naruto won't be expecting this". Sasuke states as he's jumping from tree to tree clenching and unclenching his fist as he feels the surge of power shoot to his eyes. He finally lands in a clearing where he spots a pond. The Uchiha walks over to the pond to get a good look at his new eyes. He smirks in satisfaction at the combined pattern of his brother's tome and his own.

He then turns to take off towards the closets chakra signature when he notices a gleam of light in the reflection of the pond. Sasuke glances up to see the same gleam of light in the sky.

'The hell is that? Must be some kind of jutsu.' He thinks to himself. "It's useless to these eyes though". The avenger readies himself to dodge as he places his hand on the hilt of his sword, but before he can move the light shoots down and engulfs sSasuke before he can move an inch.

Darkness... his body feels extremely heavy.

"GET UP! I SAID GET UP!" An angry female voice invades his senses.

'This woman must have a death sentence' the avenger thinks to himself as he's slowly regaining his senses. Upon further inspection Sasuke notices that he's lying face down on a cold tiled floor. 'Weird, is this some kind of teleportation justu?'

"GET UP STUPID! I WON'T ASK AGAIN!" The unfamiliar female voice shouts again.

Sharingan eyes open up to face cold white floor. 'Stupid huh, I guess it's time to test nii-san's eyes'. The raven haired teen stood up his bangs shadowing over his eyes, but not hindering his vision in any way. Sasuke slowly turned around to face the girl ready to test out a genjutsu but his eyes went wide with confusion when he faced her. He had finally took in his surroundings. He was no longer in the elemental nations, that much he could tell.

"Hey! Come on! I spent all this time transporting you here since you're the only capable master that responded to my summons!" The girl yelled. "Also my name is Olga, I would ask you for your name but we have to skip formalities. Now follow me I'll explain on the way!" The girl now identified as Olga ran down the hallway with standard human speed.

Sasuke shook his head and caught up with her easily (being a ninja and all). 'Why am I always meeting these overbearing women?' He thought to himself.

They rounded a corner "So as I stated before I summoned you here, don't ask how because I'm skipping that part". She began, sasuke casually rolled his eyes. Olga took note of that but didn't comment. They rounded a corner and stopped at a door.

Sasuke glanced up at the sign over the door, it read 'Hero Summons'. Olga pulled out a key card and swiped it on a mechanism next to the door. The door slid open and she entered beckoning Sasuke to follow. The avenger shrugged casually following behind her.

She motioned for him to sit in a chair as she did the same. The Uchiha glanced around the room he noticed it was a standard white room but what really stood out was the shield in the middle of the floor. It was connected to two wires that were also connected to two strange boxes.

"Alright since we're pressed for time I'll give you the short version, all questions will be reserved until the end of my explanation. For starters you are now in Chaldea." Olga began.

'Chaldea? That doesn't sound familiar' the avenger furrowed his brows in irritation.

"Pay attention! Now you are the second master that I've had the pleasure of speaking to one on one" she stated rather solemnly.

'Master? I really hope this isn't some kind of bdsm thing' the avenger began to shiver.

"Now the first master was slain in battle along with his servant... before you ask a servant is a summonable being either from the future or the past that is usually deemed as a hero. He was slain by Artoria alter. A king from a different era who was summoned as an evil servant. We're not sure how she was summoned in an alter form but nonetheless being in her alter form made her stronger and ruthless." She continued as wiped a tear from her eye.

"This facility used to house at least 50 other masters until an unforeseen accident took place that lead to only one master and one servant being left alive. A few seconds after the accident those two along with myself were transported to Fuyuki, a desolate place with no other human life. We then battled another servant and won with the help of another heroic spirit. It was then we faced saber alter, those two put up a good fight but ultimately we lost. All I have left of them is that shield" Olga motions to the shield on the floor. "So now I need you and your servant to defeat saber and restore order". She finished as she dug into her pocket, and pulled out 9 shiny gems.

Olga extended her hand and gave them to Sasuke who inspected these 9 tiny gems. "You may now ask your questions" Olga concluded.

The avenger had many questions but he settled on asking two. He sighed as he began "Ok so I'm guessing these stones have something to do with summoning servants? Correct?" The Uchiha asked. Olga nodded

"Yes you use those gems in order to summon a servant. They are called saint quartz, I gathered them in Fuyuki. They're extremely rare so don't expect to find them just anywhere. Also you need 3 to conduct a summoning so you only have 3 chances at summoning a servant." Olga finished and faced Sasuke waiting for his follow up questions.

'3 huh. She only gave me 9. I wonder what happens if I don't summon a servant with the limited amount she gave me? Screw it I'll ask if the problem arises. Guess I'll ask my last question before I summon' the avenger thought to himself. "How do I get back home" he asked. Olga grimaced and Sasuke noticed. 'Not good' he thought.

Olga began "Well once you defeat Artoria I can fully explain the mission and how you getting home is somewhat possible...come on let's summon." She quickly got up and walked over to the shield. The Uchiha's eyes darkened at her retort but he got up anyway and followed.

'No point in getting upset now, I'm stuck here for awhile' the avenger concluded.

"Now they're are several classes of servants They include archer, saber, lancer, berserker, caster and rider. Each have their own strengths and weaknesses. Also you may get a craft essence which is an equippable item that can strengthen your servant. Unfortunately it'll be random when you summon so you could potentially summon 3 craft essences and well...let's not think about that." Olga forced a smile

'This is ridiculous why can't I just take down this Artoria king? She can't be any stronger than Kakashi' Sasuke mused 'whatever I'll just get these 3 quartz ready'

"Ok now if you summon a servant you'll get a marking on your hand. This marking is called a command seal. You get three, be careful if you use all three in the course of a day your servant depending on their nature can choose to disobey, attack or event try to kill you. Don't worry though one restores every 3 days."

'...really? Try to kill? I'd love to see them try' Sasuke inwardly scoffed.

"Enough dawdling! Now to summon place 3 quartz on the shield and step back"

Sasuke did as he was told and took a step back. A blinding light engulfed the room, after 3 seconds it died down. Laying on the shield were 3 black keys. Sasuke blinked owlishly. "I'll assume this is a craft essence?" The Uchiha asked.

Olga nodded and picked up the keys, she montioned for him to summon again and Sasuke nodded. 'Really black keys? He's wasting the quartz I risked my life gathering. He better not screw this up or I'll send him to fight Artoria alone! This is the reason I neglected to ask him his name. He seems useful but he I'm pretty sure he's expendable!" Olga inwardly yelled.

This time when Sasuke placed the quartz on the shield the room was enveloped in a rainbow light. It lasted for 10 seconds before it died down. Standing before Sasuke and Olga was a woman with white hair that stopped at the back of her knee caps, and piercing yellow eyes. Her clothing consisted of black skin tight armor that covered from her neck to her waist, it didn't cover her legs in the slightest. She wore a cape that donned an emblem that Sasuke had never seen, at the neck of the cape was fur. Underneath the armor Sasuke guessed was a half skirt because it covered the outside of her legs but it had a long opening in the middle that didn't cover her inner thighs. He decided against checking if covered her panties. She also wore stockings that stopped just above her knee. In her left hand was a sword, in her right hand was a flag.

The servant smiled at Olga cruelly and began to speak "Servant, Avenger. I answered your summoning.… Why do you make this face? Here, the written contract" she extended a piece of paper Sasuke assumed was the contract towards Olga. Olga didn't say anything, she was frozen with fear.

Sasuke sighed and decided to speak up. "She won't be signing the contract avenger."

"Oh" came the angelic voice of the avenger as she just realized Sasuke was in the room. "And why is that boy?" She turned her cruel smile towards Sasuke who was completely unfazed by it.

"Because I summoned you" was his retort. He emphasized this by showing the newly formed command seal to avenger who kept her smile in place. She raised her left eyebrow a bit and extended the contract toward Sasuke who casually grabbed it from her hand. Avenger began to look Sasuke over as a pen appeared out of nowhere and he promptly signed said contract.

'He seems too frail to be my master, he's not even exuding any mana.' Her smile turned into a dark frown. 'No wonder I was summoned at 50% of my power. No. I can't serve anyone who I deem weak. I won't have a burden of a master. I'll kill him and take those damn command seals.' The female avenger's grip tightened on her sword.

As the contract disappeared confirming his signature and signifying the bond between the two avengers Sasuke noticed the female avenger's grip on her sword tightened. He knew what this meant. She was preparing to attack.

A second later the female avenger threw herself at Sasuke, her sword coming at him in an arching slash. 'Her speed...it's that of a Kage.' Sasuke barely had enough time to press a seal on his wrist as his own sword appeared and the sound of metal impacting metal echoed on the room.

And End of Chapter 1

Tell me what you guys think


	2. The Ultimatum

Alright guys let's clear a few things up. First in this story Jalter will be faster than Sasuke but he will have more endurance. Jalter's speed grade is an A in her servant file so we'll balance Sasuke's speed by grading his as a B+. Second the current Sasuke is Sasuke right after he left the cave after transplanting Itachi's eyes so he won't have rinnegan. Also he will be slightly weaker than he should be at that moment in time but that will be explained in later chapters. Thanks to everyone that left a review it really helps me in terms of things that i need to fix so keep them coming. Enjoy Chapter 2

Chapter 2 "The Ultimatum"

A second later the female avenger threw herself at Sasuke, her sword coming at him in an arching slash. 'Her speed...it's that of a Kage.' Sasuke barely had enough time to press a seal on his wrist as his own sword appeared and the sound of metal impacting metal echoed in the room.

'She's strong' Sasuke used the back of his sword to parry avenger's sword so it embedded into the tiled floor. He looked over to Olga who was a few feet away still frozen in fear watching avenger. He quickly grabbed Olga by the waist and jumped a few feet back to gain some distance. Sasuke had to weigh his options. He activated his sharingan and waited for the female avenger to move.

The female Avenger had her eyes fixated on her sword still embedded in the ground. 'This little chicken shit might actually be worth my time if he's able to parry my blade, he's also fast and those eyes are quite interesting.' The female avenger looked up to meet Sasuke's gaze. She smiled her signature cruel smile and sheathed her sword. Sasuke watched in interest.

"You know chicken shit we might have gotten off on the wrong foot" she began. Before Sasuke could retort about the rude nickname Olga spoke up.

"Ya think!" Olga yelled. "First why are you attacking him if you answered his summons in the first place?" she questioned.

Avenger glared at Olga who froze up again. She then turned her attention back to Sasuke "Chicken shit what's your name, because I'm not calling you master since I'm clearly stronger".

Sasuke held his glare for a few seconds before answering. "My name is Sasuke Uchiha." Olga looked up at him seeing as how this was the first time she heard his name as well.

Avenger did her trademark smile again. 'Sounds Japanese, but I'm pretty sure no Japanese native has red eyes I'll ask about that.'"Those eyes-" The female avenger began but before she could attempt to ask Sasuke spoke up again.

"It's customary when someone gives their name you're supposed to respond with your own" He spoke with his Sharingan still active waiting for any threatening move.

Avenger's rage spiked again as her shoulders shook with anger. 'Talking to me as if we're equals. Fine I'll play along.' "Well I don't trust you with my full name since it would put me in danger if I revealed it to someone who could potentially put me in danger. But I can give you a nickname to call me. You can refer to me as Jalter." Jalter watched Sasuke, gauging his reaction.

He then turned to Olga who still had her eyes fixiated on the newly named Jalter. "What does she mean I could potentially put her in danger?" he asked.

Olga hesitantly took her eyes off of Jalter to answer Sasuke. "Most heroic spirits sometimes refuse to give their name to their masters if they feel their skills as a mage are inadequate, it can also give their enemies clues on their weaknesses. I can see her reasoning. You don't give off a mage vibe and I can't feel any magic coming off of you. How do you move so fast if you're not a mage? Are you using reinforcement magic on your legs?" She began to ask, before Jalter interrupted her.

"Hey Master" she called sarcastically. "You're not a mage but you move quickly and seem to have some skills with a sword." She began. "I'll give you an ultimatum if you can land a scratch on me I'll tell you my name, but if you can't scratch me within..." she tapped her chin in a cutesy fashion "two minutes, yeah I'll give you two minutes to land a scratch on me or you lose." She finished

"What do you win if I lose?" The Uchiha asked.

Jalter gave a girlish smile that didn't fit her crazed smile she kept giving him earlier. Sasuke knew her answer spelled heavy consequences.

With her girlish smile still intact she replied "If you lose I take your command seals and your hand to go along with it".

Olga visibly paled. Sasuke showed no outward indication that he was nervous. This worried Olga even more, This was not her day. "Saske you can't fight a servant" Olga began before he turned back to her.

"It's Sasuke not Saske, and I'm not going to fight her I'm going to land a scratch on her". He retorted.

"That's still fighting stupid!" Olga yelled. The Uchiha gained a tick mark on his head.

"You know when Jalter showed up she said she was an Avenger. That's not a servant class you told me about." Sasuke began changing the subject.

"I know, I'll have to look into that" Olga answered.

"Also she doesn't look like a hero to me. If anything she looks more like a villain." Jalter visibly stiffened at Sasuke's comment.

"I know, she also has the same eyes as Artoria alter" Olga replied as she grimaced. At this Jalter smirked.

"So there's another alter around huh? I'll deal with you first chicken shit then I'll deal with that other alter." Jalter gripped at the hilt of her sword in anticipation of killing another alter. "Let's s do this chicken shit, I don't have all day."

Olga gave one more are you sure about this glance at Sasuke before he gave a nod of approval. She sighed as she led the two supposed fighters to the training room.

Training Room

Jalter cracked her knuckles in anticipation "You ready chicken shit?" they were in a large white room with nothing in it except an exit door and a large window. Currently Olga was behind the window

'I hope you know what you're doing Sasuke' The white haired girl (Olga has white has as well, I forgot to give a description of her) thought.

Sasuke currently had his eyes closed. His sword was now on the back of waist (like how he carries it in shippuden). 'She'll definitely hate me for this but I have to surprise her and end this quickly, no need in using my full power since I have yet to test the limits of Nii-san's eyes. The faster I get this over with the faster I can beat Artoria alter and get back home.

Olga's voice came over the loudspeaker "Fighters ready?" Jalter smirked as bounced in place ready to burst at Sasuke with her superior speed again. "Begin!"

Jalter took off with speed twice as fast as when she attacked Sasuke the first time. Olga couldn't even follow but Sasuke watched her every move with percision. One second Jalter was 20 feet away from Sasuke the next second her fist was 5 centimeters away from knocking his head off.

'She's faster than before' with his base sharingan activated Sasuke attempted a paralysis sharingan justu but it didn't seem to affect Jalter.

She smirked again 'oh so you do use magic huh? To bad I have magic resistance chicken shit, it's the end for you.'

Sasuke was inwardly panicking 'Crap, crap, crap. Using Eternal mangekyou sharingan would be to taxing on my chakra.' The fist was 4 centimeters away. 'I hate that I have to resort to this. What would the dobe do?' 3 centimeters away, 2 centimeters away.

Jalter could feel her victory.

Then a light went off in Sasuke's head.

One second Jalter was a centimeter away from punching a hole through Sasuke and the next second she was punching a whole through her own cape.

Sasuke appeared behind her and with a kunai slashed at Jalter's back but she moved a bit to the side at the last second. Sasuke's kunai made contact with another part of Jalter.

They both landed on the their feet at the same time. "Did I just cut through-" before Sasuke could finish or bring his arms up to guard Jalter turned around with her Class A speed and puched Sasuke into the wall. Her face was bright red with embarrassment.

Jalter glared at him as his vision started to fade from the unexpected hit and the collision with the arena wall.

"You win Sasuke" Jalter yelled out still bright red as a tomato. As she turned to leave Sasuke saw that his kunai did indeed cut through her spandex shorts. With his sharingan activated he saw the small cut revealed pure white flesh through black spandex. On further inspection the flesh a had a tiny cut that drew blood. He landed a scratch on her left

buttcheek.

"Yeah...I'll count that as win as well" Sasuke coughed out as the darkness took over and he blacked out.

 **Sasuke's dreamscape**

Sasuke opened his eyes to the loud crying of a child. Like any ninja he took in his surroundings, currently he was laying on the ground in a what seemed to be a village 'Why do I always wake up on the ground' he asked no one in particular. This wasn't Konaha or any hidden village he had seen. This village had a different air to it. The air felt heavy almost suffocating. Sasuke decided to look for the source of the crying. He was never simpathetic but when it came to children crying even he had a heart.

The Uchiha continued searching for the source of crying, with each step he took it got louder. 'It's strange that I haven't ran into anyone else here, it's like this village is deserted excluding this crying child.' His thoughts were answered when he rounded a corner. At least a hundred of soldiers had been slain, none of the were moving.

He started having flashbacks of the Uchiha massacre. 'I can't let this child be exposed to this, I have to find him or her and get out of here. Sasuke decided jumping from rooftop to rooftop was more time efficient. As he got closer to the crying he spotted the source. A little girl was up up on a hill.

Sasuke ran towards the girl and she looked up at him in fright when he tapped her shoulder.

'This girl looks familiar, I don't know where I've seen her before' The Uchiha thought to himself. "Hey where's your mom and dad? We have to get you out of here? The Uchiha asked.

She looked up at him with sad golden eyes and replied. "I don't have a mom or a dad." She put her head back down and began to cry "I have no one to protect me, I'm all alone". She said through sobs.

Sasuke's heart ached a bit. This child reminded him of himself. "I'll protect you then." He stated.

At that the child stopped crying. She looked up fresh tears ready to spill down her eyes "you will?" She asked as she hiccuped.

Sasuke smiled. "Yeah" The little girl extended her tiny pinky.

"Pinky promise?" She asked. The Uchiha smirked

"Sure pinky promise" Sasuke extended his pinky and they intertwined pinkies.

 **Darkness**

Sasuke awoke to the white ceiling of an unfamiliar room. He was back in Chaldea, the village, the soldiers, the little girl it was all a dream.

"Finally up huh?" Sasuke turned to his right and saw Olga smiling at him sitting in a chair.

"Yeah, guess it's time to get ready for that mission" The Uchiha concluded.

Olga nodded "I've already briefed Jalter on the mission, she agreed to help" Olga smiled as she kept giving him a strange look. "She really did a number on you. Broke 4 ribs from just one punch. I'm surprised there wasn't any damage to your back after your impact with wall" Olga finished.

'That's because I activated Susanoo at the last second, but you don't need to know that, I gotta keep a few secrets in case Jalter wants to attack me again...speaking of Jalter'. The avenger looked back towards Olga. "Speaking of Jalter where is she?" The Uchiha asked.

Olga gave Sasuke a smile that he didn't like. "Well after she told me that you summoned her at half her power, then you two had your little skirmish. This lead to her having next to no mana left" Olga could see the confusion in Sasuke's eyes but she continued. "During your match she explained to me that you were trying to use magic on her." Sasuke looked even more confused than before. Olga continued "I told her that the second best way to receive mana was skin to skin contact with your master."

Sasuke paled at the implication. It was then that he noticed the extra weight oh his left side, two mounds of flesh were pressed against his left arm. How had he not noticed it before? Olga's smile deepened as she pointed behind her. Sasuke's suspicions were true because behind Olga were all of Jalter's clothes/armor neatly folded on the chair.

He begrudgingly turned to left and was face to face with a sleeping naked Jalter. Olga choose this moment to make her way to the exit but she stopped shy of the door. "I wonder if she's a morning person?" was her lingering question as she walked out the room.

Sasuke watched as Jalter started to stir in her sleep. He breathed a sigh of relief when she went still…..Then her golden eyes shot open.

End of Chapter 2

Next Chapter they enter Fuyuki so stay tuned and don't forget to leave a review.


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